Astronomers using NASA's Chandra X-ray Observatory have found evidence for a population of old stellar black holes. The discovery provides new insight into the nature of stellar black holes, which is a class that can produce as much energy in X-rays as what a million suns could radiate at all wavelengths.

An agreement was signed by ESA and the Japanese Aerospace Exploration Agency (JAXA) for cooperation on Astro-H, an important mission that will provide a unique opportunity for probing extreme phenomena in the Universe.

NASA's Swift satellite puts faraway stars and galaxies under a new lens. A combination of X-ray and ultraviolet observations from NASA's Swift satellite allow researchers to gain a more detailed look at specific stars and their activities.

Columbia launched from Kennedy Space Center on December 2, 1990 at 1:49 AM EST and landed at Edwards AFB on December 10 at 9:54 PM PST. The shuttle orbited 144 times at an altitude of 190 nautical miles at an inclination of 28.45 degrees and travelled 3.7 million miles. The mission lasted 8 days, 23 hours, 5 minutes, and 8 seconds.
The primary objectives were round-the-clock observations of the celestial sphere in ultraviolet and x-ray astronomy with the ASTRO-1 observatory consisting of...

Sample Entry:
Astronomy is the scientific study of stars, planets, comets, galaxies, and other phenomena that occur outside Earth's atmosphere (e.g. cosmic radiation). Astronomy deals with the evolution, physics, chemical makeup, meteorology, and motion of celestial objects, and also the formation of the universe. The word Astronomy comes from the Greek words astron (meaning "star") and nomos (meaning "law").
Astronomy is one of the oldest sciences. Since the dawn of man, people always...

X-Ray Astronomy -- Although the more energetic X-rays (E > 30 keV) can penetrate the air at least for distances of a few meters (they would never have been detected and medical X-ray machines would not work if this was not the case) the Earth's atmosphere is thick enough that virtually none are able to penetrate from outer space all the way to the Earth's surface.
X-rays in the 0.5 - 5 keV range, where most celestial sources give off the bulk of their energy, can be stopped by a few...

X-ray Pulsar -- This dramatic artist's vision shows a city-sized neutron star centered in a disk of hot plasma drawn from its enfeebled red companion star.
Ravenously accreting material from the disk, the neutron star spins faster and faster emitting powerful particle beams and pulses of X-rays as it rotates 400 times a second. Could such a bizarre and inhospitable star system really exist in our Universe?
Based on data from the orbiting Rossi X-Ray Timing Explorer (RXTE) satellite,...

Gamma-Ray Burst -- In astronomy, Gamma-ray bursters (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow.
They occur at random positions in the sky several times each day. They are now believed to result from tremendous explosions in far away galaxies, during the creation of a black hole from a dying star or two colliding neutron stars. The black hole, surrounded by a rotating disk of matter falling into it,...